17 June, 2017

China's quantum satellite establishes photon entanglement

A
team of Chinese scientists have realized the satellite-based
distribution of entangled photon pairs over 1,200 kilometers. The
photon pairs were demonstrated to be still entangled after travelling
long distances.

This
satellite-based technology opens up bright prospects for both
practical quantum communications and fundamental quantum optics
experiments at distances previously inaccessible on the ground, said
Pan Jianwei, an academician of the Chinese Academy of Sciences.

The
achievement was made based on the world' s first quantum satellite,
Quantum Experiments at Space Scale (QUESS), also dubbed Micius,
launched by China on August 16, 2016, and was published as a cover
article in the latest issue of academic journal Science.

This
experiment was made through two satellite-to-ground downlinks with a
total length varying from 1,600 to 2,400 kilometers. The obtained
link efficiency is many times higher than that of the direct
bidirectional transmission of the two photons through
telecommunication fibers, said Pan, who is also the lead scientist of
QUESS.